I dont think he wrote off the renovations, as that would be problematic from a tax perspective. what he probably does is charge LMG what would be considered a reasonable rate to film on at his home and he makes money back that way.

i.e. this came up when he was talking about the wall tv. he couldn't just bill it to lmb and store it at home, he would have to pay for it out of pocket and then charge LMG for every time they used it.